The successful operation of satellite communication systems requires the use of components that are capable of withstanding severe, and often rapid, changes in environmental conditions (e.g. rapid thermal transients in response to changes in solar exposure (full sun-vs-eclipse)). Because of these demands, structural elements that are acceptable for terrestrial use are often unsuited for spaceborne applications, without a substantial modification of hardware design. This problem is particularly accute with respect to the electrical components of antenna structures which employ metallic surfaces for signal coupling functions (e.g. aluminum waveguide feeds) and for the radiating components (e.g. aluminum/copper-surfaced horn elements). Because of the substantial magnitudes of their coefficients of thermal expansion, the metallic structures suffer from inherent dimensional instability; the resulting physical distortion (e.g. warping, bowing of the horn and feed structures) changes the field pattern characteristics of the antenna, thereby adversely affecting its performance. Moreover, repeated thermal cycling of the structures may lead to structural fatigue and eventual separation of components of the antenna structure.
One approach for dealing with this problem has been to provide error tolerance performance through the use of a large number of radiator and intercoupled feed elements for which a complex support framework is required. This approach is, in effect, a brute force solution, adding to the antenna considerable size and weight, precious commodities from an earth to space transport standpoint.